An oil painting by a renowned Welsh artist whose works have been sold for tens of thousands of pounds, has been stolen from London's Southbank Centre.

Landscape At Llanaelhaearn, painted by Sir Kyffin Williams, was discovered missing after a member of staff found the broken picture frame hidden in a toilet cubicle in Royal Festival Hall.

It is believed the work was taken from the hall at the end of September.

Police said they believe the thief will try to sell the piece.

Det Con Ray Swan, from Scotland Yard's Art and Antiques Unit, said: "I urge anyone who is offered the painting to report the matter to us immediately, or contact us if you know anything about the theft or the painting's whereabouts."

The painting, which was on loan from the Arts Council Collection, had been on display at the centre since November last year.